......food related career that engineer works in (an engineering job in food industry~)?

most plentifully, at a food (loosely used) processing "entity"

the folks selling at the farmers' market probably don't employ an engineer to figure out the best way to pack the truck, but General Mills to general raisins, that's food production on a mass scale and engineers are needed for process development and control. plus the whole "plant engineering" / infrastructure bit including more direct elements like packaging and material handling.

bakeries, grains, frozen foods, wineries, etc. - when the business reaches a "size" then some "management & organization" is needed and those are the entities that hire the engineers to figure out how to make true all the stuff the marketing whizzies dream up . . .